2019 Volume 88 Issue 11 Pages 735-739
The infrared convergent heating floating zone (IR-FZ) method is a crucible-free zone melting method. The control of the dopant segregation is possible by using a solvent with a suitable composition. In the conventional IR-FZ, however, the molten zone, which is maintained between the feed and the grown crystal by the balance of the surface tension and the gravity of the melt, is so unstable that the typical diameter of the grown crystal is 6〜15 mm at most. Slight modifications of the convergent heating such as the convergent position and tilt of the ellipsoidal mirrors was found to be quite effective to improve the diameter of a grown crystal up to the inch level.